Industrial process control systems are used to monitor and control industrial processes of the type used to produce or transfer fluids or the like. In such systems, it is typically important to measure “process variables” such as temperatures, pressures, flow rates, and others. Process control transmitters measure such process variables and transmit information related to the measured process variable back to a central location such as a central control room.
One type of process variable transmitter is a pressure transmitter which measures process fluid pressure and provides an output related to the measured pressure. This output may be a pressure, a flow rate, a level of a process fluid, or other process variable that can be derived from the measured pressure. The pressure transmitter is configured to transmit information related to the measured pressure back to the central control room or other location. Transmission is typically provided over a two-wire process control loop, however, other communication techniques may be used including wireless transmission.
Generally, the process pressure is coupled to the process variable transmitter through some type of process coupling. In many instances, a pressure sensor of the transmitter is fluidically coupled to the process fluid either through an isolation fluid or by direct contact with the process fluid. The pressure of the process fluid causes a physical deformation to the pressure sensor which generates an associated electrical change in the pressure sensor such as capacitance or resistance.
One particularly challenging environment for pressure measurement is applications which have a very high working pressure. One such application is the subsea environment. In such applications, the static pressure to which the process equipment is exposed can be quite high. Further, the process variable sensor may be exposed to a very broad range of temperatures. In such applications, various industry standard form factors are used for configuring the process variable transmitter. One typical configuration includes a pressure sensor positioned at a distal end of a probe. Transmitter electronics are carried in an electronics housing which is spaced apart from the probe. Electrical connectors extend from the electronics housing and couple to a pressure sensor carried in the probe. In many instances, it is difficult to reliably electrically connect to a process variable sensor carried at the distal end of the probe. Such connections may be difficult to achieve and may also be prone to failure. Further, in such configurations, size constraints may also present a challenge.